The NPC menus as they appear in the Trash Panda GUI.
From the Hypixel Pit Wiki

NPCs, short for "non-player characters," are characters scattered around The Pit that serve assorted purposes.

Most NPCs offer trades and upgrades, but some have more miscellaneous purposes.

The list of NPCs is as follows:

SpawnItems (Non-Permanent)Spawn – SouthAllows the player to access the Item Shop.
Upgrades (Permanent)Spawn – SouthAllows the player to access the Upgrades Shop, containing perks, passives, killstreaks, and megastreaks.
Quest MasterSpawn – EastAllows the player to access quests and contracts.
StatsSpawn – EastAllows the player to view their statistics.
PrestigeSpawn – NorthAllows the player to prestige and access the renown shop.
The KeeperSpawn – WestAllows the player return to the Hypixel Main Lobby without using commands.
Leaderboard Picker (rabbit)Spawn – EastAllows the player to change the currently displayed leaderboard.
Castle map exclusiveThe KingPort – (−110, 79, −6)Allows the player to start and complete the King's Quest.
BakerLocation variesAllows the player to turn in materials to receive a Mini Cake.
SewerfishSewersLocation variesAccepts 64 Sewer Rubbish in exchange for Fresh Sewer Pants.
Hay (salesman)City – (50, 68, 91)Removes all Packaged Bale from your inventory, giving 16 gold per bale removed.
Bread (salesman)City – (89, 66, 56)Removes all Yummy Bread from your inventory, giving 24 gold per loaf removed.
Fish (salesman)City – (33, 66, 61)Removes all types of fish from your inventory, giving 1 gold per fish removed.
Genesis map exclusiveAngelSpawn – South (−12, 86, 18)Allows the player to access the Angel faction menu.
DemonSpawn – North (12, 86, −17)Allows the player to access the Demon faction menu.

The possible locations of the Baker are as follows:

Spawn NPC menus can also be accessed through the use of the Trash Panda enchantment.